JorgeB

We highly encourage to use MTU 1500 for the main NIC, eth0, you can then use 9000 for the 10GbE NICs, I for example always have a gigabit NIC with MTU 1500 as eth0 and then my 10GbE LAN with MTU 9000, if you want to keep using that make sure everything in the LAN supports that and is correctly configured.
 
You should upgrade back to v6.10.3, delete/rename /boot/network.cfg and reboot to see if both NICs get detected.
 
Also switch to ipvlan (Settings -> Docker Settings -> Docker custom network type -> ipvlan (advanced view must be enabled, top right)), I see some call traces in the log related to that.
 
After that post new diags after you see the problem.

Sep 28 19:06:49 Executor-Server emhttpd: shcmd (740): /sbin/wipefs -a /dev/nvme0n1 Sep 28 19:06:49 Executor-Server root: wipefs: error: /dev/nvme0n1: probing initialization failed: Device or resource busy Sep 28 19:06:49 Executor-Server emhttpd: shcmd (740): exit status: 1 Sep 28 19:06:49 Executor-Server emhttpd: writing MBR on disk (nvme0n1) with partition 1 offset 2048, erased: 0 Sep 28 19:06:49 Executor-Server emhttpd: re-reading (nvme0n1) partition table Sep 28 19:06:50 Executor-Server emhttpd: error: mkmbr, 2196: Device or resource busy (16): ioctl BLKRRPART: /dev/nvme0n1 Sep 28 19:06:50 Executor-Server emhttpd: shcmd (741): udevadm settle Sep 28 19:06:50 Executor-Server emhttpd: shcmd (742): /sbin/wipefs -a /dev/nvme0n1p1 Sep 28 19:06:50 Executor-Server emhttpd: shcmd (743): mkfs.btrfs -f /dev/nvme0n1p1 Sep 28 19:06:50 Executor-Server root: ERROR: '/dev/nvme0n1p1' is too small to make a usable filesystem  
It's saying device in use, so it's not wiping it completely and then using the existing partition 1 which is too small, try rebooting and running blkdiscard right after boot, if it still doesn't format post new diags.

The below sometimes helps:
 
Some NVMe devices have issues with power states on Linux, try this, on the main GUI page click on flash, scroll down to "Syslinux Configuration", make sure it's set to "menu view" (on the top right) and add this to your default boot option, after "append initrd=/bzroot"
nvme_core.default_ps_max_latency_us=0 e.g.:
append initrd=/bzroot nvme_core.default_ps_max_latency_us=0
Reboot and see if it makes a difference.

You cannot start the array with only parity assigned, if you are going to use a single device for now assign it as disk1.

ata6: SError: { UnrecovData 10B8B BadCRC } This is usually the result of a bad SATA cable.

I believe it's a known issue, it works with 10/11.

Yep.

Now unassign all cache devices, start array, stop array, re-assign both cache devices and post new diags after array start.

Stop array, unassign all cache devices, start array, stop array, re-assign all cache devices and start array, that should do it.

With nocow it will disable cow for any data written to that share.
 
Like any other file, any blocks are written to both devices.
 
xfs or btrs nocow might perform a little better, but xfs is single device only and btrfs nocow as mentioned should be avoided, note that a mirror is for redundancy, you still need backups of anything important.

Yep, looks like it's Plex scanning for media:
 
nobody 26599 36.3 0.0 117064 59060 ? DNl 08:38 0:17 \_ /usr/lib/plexmediaserver/Plex Media Scanner --  
It's now reading disk10 @ 120MB/s

Check filesystem on disk1.

According to diags disk2 was never formatted, it needs to be formatted before use.

btrfs check --repair should only be used if told to do so by a btrfs maintainer or as a last resort, it can do more harm then good, best bet is to backup and re-format the pool.

Unraid doesn't support WiFi but you can get a WiFi client AP with Ethernet ports that you can then connect to the wired NIC.

Nothing relevant logged and the above really makes think of a hardware problem, crashing after a few minutes with the array and services stopped, don't remember ever seeing a similar case that wasn't hardware related.

That suggests the flash drive was not correctly created, try with a different one, just with a new install, don't restore anything, just to see if it boots.

You must format disk1 before use, below array stop button.

That suggest the SSD you are using is just slower, suggest getting one known to perform better, like the Samsung 870 EVO or Crucial MX500 for example.

Try booting in safe mode to rule out any plugin issues.

Usually you just need to bring the device back online and run a scrub, assuming there are no "nocow" shares, more info here.

Backup config folder from current flash drive, redo it with v6.11.0 using the USB tool or manually then see if it boots, if yes restore the config folder from the backup.

If the diags didn't finish get the syslog:
cp /var/log/syslog /boot/syslog.txt  

RAID controller is still changing the devices names, and that is the problem, e.g. parity it was:
 
WDC_WD80EFAX-68LHPN0_7SGMN7JC  
and now is :
WDC_WD80EFAX-68L_7SGMN7JC_35000cca252c8ef0a  
You can do a new config but will have issues again if you change the controller in the future, we recommend using a true LSI HBA.